The strength of individual jets can be adjusted in 3 ways. The jet aeration controls on the top of the spa allow air to mix with the water stream making the jet more powerful while at the same time introducing thousands of tiny bubbles into your spa. The massage control valve or valves on the top of your spa allow you to control the amount of water diverted to different seats, allowing you to adjust the power of each jet. Experiment and you will soon work out which jets work together. Turning the outside rim of each adjustable jet will adjust the flow from full to off and all strengths in between. If you want to swap different jets around the spa to create a different type of massage you can remove the jet faces by turning the jet off then twisting it sharply and then unscrewing the face. You can only swap jets with the same diameter.
Many spas have waterfalls and aromatherapy. If your spa has these features you will find two other controls at the top of your spa. The waterfall control valve, which is slightly larger than the jet aerator controls, turns the waterfall on and off. The aromatherapy fitting mixes fragrances with your air bubbles when its turned on and the air bubbles are also on. When fitting the aromatherapy for the first time or replacing the canister, be sure to turn off the bubbles and remove the clear cap on the end of the canister before inserting it. Use the handle to turn the fragrance on and adjust the level of aroma entering the spa.